The present invention relates to electrical resistance welding and, more particularly, to a welding apparatus having interchangeable welding modules.
U.S. Pat. No. 2,850,619 issued to M. S. De Lucia on Sept. 2, 1958 shows an electric resistance welder having two welding electrodes. The electrodes are generally designed to perform a number of different welding operations; however, depending on the shape of the parts to be welded, it is often necessary to replace one or both of the electrodes with electrodes that are specially configured to perform a particular welding operation. The changing of welding electrodes and the alignment of the electrodes after such a change are time consuming and inefficient. It is therefore desirable to be able to change electrodes rapidly to perform a number of different welding operations requiring different electrode configurations, and to effect the electrode change without requiring realignment of the welding electrodes.